Internal-combustion engine.



H. C. GIBSON.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED 111w. so, 1908.

965,135. Ptented July 19, 1910;

INVENTOR.

A TTORNE Y *oivrrnn STATES PATENT OFFICE.

HUGO C. GIBSON, OF NEW YORK, N. Y.

INTERNAL-COMBUSTION ENGINE.

To all whom it may concern:

Be it known that I, HUGO C. GIBSON, a British subject, residing in theborough of Manhattan, city and State of New York, have invented certainnew and useful Improvements in Internal-Combustion Engines, of which thefollowing is a description, rel"- erence being had to the accompanyingdrawings, forming a part hereof.

My invention pertains to devices and constructions which would usuallybe used in connection with internal combustion engines, but likewise ofbroader application; while in particular their use in conjunction withengines is most advantageous when enibodied on an automobile.

In the form of my invention herein shown and described is illustratedthe use of my in vention in what is generally known as a mull'ler orexhaust silencer for an internal combustion engine. In this connectionit well-known that for various practical reasons it is not, in thegeneral use of engines, particularly on automobiles, feasible to exhaustthe products of combustion directly into the air from the cylinder. Thenoise is one serious objection, while the location of the engine isusually such as to bring a direct exhaust where the gases will beobnoxious or dangerous. The usual practice is to lead the exhaust gasesfrom one or more cylinders, through a common exhaust pipe to the rear ofthe vehicle, or in other engines to any desired exi 1. The result of soconfining the gases usually causes a back pressure in the cylinderresisting the expulsion of the products of combustion. In order,however, to deaden or muttle the noise of the final exhaust, numerousforms of devices, called silencers or muillers, have been used which cangenerally be described as involving battle-plates against which the gasis impinged and which divide a box into alternating compartments, orotherwise necessitating a circuitous, irregular path with twisting andturning before the final outlet. Such devices cause some and oftenconsider able back pressure in the cylinder, resisting the expulsion ofthe products of combustion, and which consequently amounts to lost workon the part of the engine. I have over come all of the objections usual.in devices of this character, and by my invention secure a substantiallycomplete niutlling of the exhaust of from an intermittent sourceSpecification of Letters Patent.

Application filed December 30, 1908.

I of expulsion, and in addition, when used with an internal combustionengine, my invention causes an average eflective vacuum which tends todraw products of combustion out of the cylinder at the time of theexhaust, which avoidance of back pressure at that time means a directgain in power for the engine. In the actual practice of my invention insuch applications, I find that measurements show a very substantialvacuum under the conditions above stated and a corresponding improvementin the operation of the engine, in connection with which the device hasbeen used.

To more specifically describe one form of my invention, I have shown inthe accompanying drawings in I Figure I. a side view of a gasoleneengine in part section, with the connections from the exhaust to themutller; Fig. II. a longitudinal section through the inul'ller shown inFig/L; Fig. III. an end view of section taken at III-III in Fig. II.

In the particular form of embodiment of my invention, which I havechosen to illustrate herewith, 1 is a gas engine, 2 the exhaust valvethereof, 3 the exhaust port, 4t the exhaust pipe connection to themuffler The mulller comprises the intake A, the conical casing B,spirally arranged deflectors or walls C, the outlet D of the conicalcasing, the spiral deflector E, the rod F and outer casing G, ends H, H,the openings J from the outer casing, muttler clamping nuts f, bracketsK and bracket clamping nuts 70.

Referring to the drawings of one particular form of embodiment of myinvention, the engine 1 may be any internal combustion engine such as amulti-cylinder engine used. in an automobile, which upon the raising ofthe exhaust valve 2 allows the passage of the products of combustionthrough the exhaust port 3, which are carried by the exhaust pipe ltothe muffler. The exhaust pipe enters the cylindrical casing of themuffler in a tangential direction, so that the gases leaving the exhaustpipe are gradually turned in their movement in the muffler by the curvedsurface of the conical casing B. They enter the conical. casing at thelarger end, and the spiral walls or partitions guide the gases in ahelical direction toward the smaller end of the case B. In this mannerthe axial direction of the moving column of gases is gradually deflectedto a smaller and smaller radius of twisting until they substantiallyconstitute a vortex atthe smaller end of the casing B. At this end,however. a peripherically large portion of the side of the casing B iscut out leaving an aperture relatively larger than the area of the inletA. Fashioned to this outlet D is a spiral deflector E, as shown in Fig.III., which guides the gases, new subject entirely to centrifugal force,outwardly into the space formed by the larger surrounding casing Gthrough which they pass to the exit from the outer casing consisting ofnumerous holes or perforations J. Convenience of manufacture is offeredby constructing the conical casing B with its internal construction andslipping the same into the cylindrical casing G and alfixing the caps IIand II to either end, and passing a rod F from end to end through thecaps H and II, while nuts 7 screwed onto either end of rod F clamp theentire mu'filer construction firmly together as a unit. For convenienceof at taching the mutiler, I have in this particular embodiment extendedthe rod F at either end so that it may engage brackets K K convenientlyattached at any suitable place to the automobile or other object, and bymeans of the nuts the muffler as a unit can be firmly attached orreadily detached from or into position. In this construction exhaustgases enter the larger end of the conical casing B, and as in the formshown I have inserted an internal smaller conical casing Z), a passageis formed between the inner cone Z) and the outer cone B, and thepartition walls 0, so that the gases are gradually turned in theirdirection of movement, but the section of the passageway is increasingas the smaller end of the casing B is approached, so that the gases mayexpand, ending gradually to reduce to atmospheric pressure. Thedimensions of the device are such that they have substantially expandednear or to atmospheric pressure by the time they reach the vortex of theend of the cone, but in so doing they have not been obstructed by anybatlie-plate and therefore their momentum has not been decreased. At thesame time the arrangement has brought the convolutions of the passagewaycompactly together, so that in the small space permissible for a deviceof this character a long passageway and ample distance for expansion andtime for expansion has been achieved. A most important point, however,is involved in the fact that the discharge from the exhaust pipe 4 intothe mutller casing is at the larger end of the conical casing, so thatany noise, owing to the inrushing gases, is notmagnified as would be thecase in originating a noise at the smaller end of a flaring compartment.As the volume and speed of inrushing gases varies with the operation ofan engine of this character, and may vary in any source of intermittentdischarge in connection with which my apparatus may be used, it is notalways possible to determine fixed proportions of the passageways or thepitch of the helix, which will give the absolutely accurate time andsize for expansion of the gases to atmospheric pressure, under all ofthe varying conditions. For such varying conditions I therefore preferto add the additional outer casing G, which receives the gases from theconical casing and from which they then find their way into the outerair, as through the perforations or any other suitable means in theouter shell. To more gradually deflect these gases from the small end ofthe conical casing 13, I adapt the spiral or evolute compartment, and tostill further aid in the gradual de fiection of the direction ofmovement, I flare the compartment outwardly toward the exit end of thelarger casing.

lVhile I have shown and fully described a particular form of embodimentof my invention in a structure which has given most remarkable resultsin actual practice, I do not wish to confine myself to the particularconstruction shown and described. In many cases it is unnecessary toinsert the inner cone 1), but the movement of the gases leaves a inertcore while the gases thus swirl out in contactwith the outer casing. Asthe initial deflection to a circular motion is at the large diameter ofthe cone B, the skin friction at the entrance of the mutl'ler isminimized and the small retardation due to contact with the surfaces isvery gradually increasing.

An important feature involved is a fact that with no obstructions, thegases pass through my muil'ler expanding as desired, and graduallyexhausting silently and under little pressure, but, maintaining theirmomentum, a practically continuous column or moving mass proceedsthrough the structure substantially unaffected by the intermittent orpulsating discharge from the exhaust port of the engine. As a result themass of gases passing uninterrupted when the exhaust valve 2 is closed,tends to create a vacuum in the exhaust pipe i.

I have found that a very substantial suction is produced in the exhaustpipe in the use of my invention, whereas in engines heretofore anobstacle to high etliciency has been a back pressure in the exnaustpipe. With my mutller it is posible to get such a suction that upon theopening of the exhaust valve the exit of products of combustion will bemore rapid than has heretofore been possible, which reduces the pressureat that stroke of the engine, and sucking out the gases as it does, hasthe effect of more thoroughly scavenging the cylinder than is possiblein the use of other forms of mufflers. 1

This is particularly advantageous in 2-cycle internal combustion enginespreventing many of the troubles which have heretofore existed.

In actual practice the substitution of my mutller for the usual form ofmultlers, has made possible increased power and greater flexibility inthe engine, readily and very substantially enabling an increase in speedof operation and other advantages.

Vhile various other forms of construction could be made to embody myinvention, it will be seen that having the stream of? gases deflected,as described, brings the portions of the passage side by side resultingin the maximum possible length of passageway for a given over-all sizeof apparatus. Under some conditions of operation I have found thatsubstantially all noise is eliminated, and the beneficial results of myinvention obtained without any additional outer casing beyond theconical casing. In its thus simple form my device consists of a piece OIbent sheet metal secured at its edges, into which may be loosely orotherwise placed a band of sheet metal which forms the spiral. In all,this comprises a device tremely cheap in construction and simple inmanufacture, and with all the very great advantage inherent to theparticular design. The structure at the same time is light and canreadily be attached to a vehicle or any suitable place in proximity tothe engine in cooperation with which it is used.

It will be noted that the gases are free to escape at the small end ofthe expanding passage, and as their momentum has been maintained, nosudden change in their direction having been caused, they issue due tocentrifugal force and practically suck the column of gases behind them.In other forms suitable deflectors made cause the sucking outlet in viewof the momentum.

As it will be seen that my invention may be embodied in various formsand constructed with various changes in design and material, and used invarious connections other than such as have been herein specificallydescribed or shown, what I claim and desire to secure by Letters Patentis:

1. In combination with an internal combustion engine, a deviceinterposed between the exhausttheretrom and the exit of gases to theair, including a passage for diverting the direction of movement of thegases and permitting their expansion substantially to atmosphericpressure at their exit, a port at their exit adapted. to permitunbaiiied passage in the direction of their velocity.

In combination with an internal combustion engine, a device interposedbetween the exhaust "from said engine and the exit of gases to the air,including a passage for gradually diverting the movement of the gasesfrom linear to vortex motion and permitting unbatlled exit of said gasesin the direction of their velocity to free air.

3. In combination with a gas engine, a mufiler having a passage thecontiguous portions uniformly increasing in section and graduallyvarying in direction to a free exit.

a. In combination with a gas engine, a mufl'lcr having a passage thecontiguous por tions of which are side by side and present a graduallyvarying axial direction and unbatlled exit.

5. In combination with a source of intermittent discharge of gases unde"pressure, a device interposed between said source and the final exit ofthe gases to the air, includ ing a spiral passage or duct, and a finalport permitting unbatlied exit in the direction o1 their velocity.

6. In combination with a source of intcrmittent expulsion of gases, adevice adapted to receive and discharge the gases including acompartment, curved walls in said compartment, an inlet to saidcompartment at its larger end, a relatively greater outlet from saidcompartmei'it at its relatively smaller end.

7 In combination with a source of intermittent expulsion of gases, meansto receive said gases and discharge same including a conicalcompartment, an inlet at the larger end of said conical compartment andan outlet for the discharge of the gases at the smaller end thereof.

8. A gas engine mui'ller comprising a conical chamber, ribs in saidchamber adapted to guide gases in a spiral direction therethrough andfrom the smaller end into the free air.

9. A muiiier comprising a conical compartment, an inlet thereto at itslarger end having a relatively smaller area than an outlet at thesmaller end of said compart ment.

10. In a gas engine muil'ler, an exhaust passage of gradually increasingsectional area surrounded by a wall forming a compartment of constantlydecreasing sectional area from the inlet end to the gas outlet endthereof.

11. A muffler including a conical compartment, an inlet from the engineexhaust to the large end of said compartment, walls adapted to guide thegases helically through said compartment, a deflecting case or cap forthe gases over the smaller end of said compartment.

12. In a muffler a conical compartment, an inlet thereto at its largerend, a deflects ing wall disposed at the gas exit at its smaller end.

13. In a muilier a truncated conical compartment, an inlet theretoadapted to deliver gases tangentially at its larger part, walls dividingsaid compartment into a passage Signed at New York this 29th day ofDecember, 1908.

HUGO G. GIBSON.

itnesses DANIEL J. GUINAN, H. Mnornronn.

